Many exercise devices require electrical power to operate features of the exercise devices. Some exercise devices receive this power from a power connection to a wall or floor plug wired to an electric utility or generator. Other exercise devices derive their electrical power from batteries. For example, many exercise cycles have a computer that reports information about a workout on a display. These computers are typically powered by a battery. Some exercise devices have other components requiring batteries, such as sending units on speed sensors.
One significant drawback to battery powered exercise devices is that the batteries must be periodically replaced. Battery replacement can be a tedious and annoying exercise for a single exercise device, and it becomes a major irritation for commercial gym operators that must regularly replace batteries in rooms full of exercise devices.